Paraffin alkylation

ABSTRACT

A process for the alkylation of alkane with olefin or olefin precursor such as an oligomer of tertiary olefin comprising contacting a liquid system comprising acid catalyst, isoparaffin and olefin in concurrent downflow into contact in a reaction zone with a disperser mesh under conditions of temperature and pressure to react said isoparaffin and said olefin to produce an alkylate product is disclosed. Preferably, the liquid system is maintained at about its boiling point in the reaction zone. Unexpectedly, the olefin oligomers have been found to function as olefin precursors and not as olefins in the reaction. Thus, for example, a cold acid alkylation using an oligomer of isobutene (principally dimer and trimer) with isobutane produces isooctane with the isobutane reacting with the constituent isobutene units of the oligomers on a molar basis. The product isooctane is essentially the same as that produced in the conventional cold acid process.

This application claims the benefit of provisional application60/313,987 filed Aug. 21, 2001, provisional application 60/323,227 filedSep. 19, 2001 and provisional application 60/334,560 filed Nov. 30,2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the alkylation of paraffinichydrocarbon feed stocks. The present invention provides both animprovement in the operating conditions and the feed stock for acidparaffin alkylations.

2. Related Information

The common objective of most alkylation processes is to bring isoalkanes(or aromatics) and light olefins into intimate contact with an acidcatalyst to produce an alkylation product. In the petroleum refiningindustry, acid catalyzed alkylation of aliphatic hydrocarbons witholefinic hydrocarbons is a well known process. Alkylation is thereaction of a paraffin, usually isoparaffins, with an olefin in thepresence of a strong acid which produces paraffins, e.g., of higheroctane number than the starting materials and which boil in range ofgasolines. In petroleum refining the reaction is generally the reactionof a C₃ to C₅ olefin with isobutane.

In refining alkylations, hydrofluoric or sulfuric acid catalysts aremost widely used under low temperature conditions. Low temperature orcold acid processes are favored because side reactions are minimized. Inthe traditional process the reaction is carried out in a reactor wherethe hydrocarbon reactants are dispersed into a continuous acid phase.

Although this process has not been environmentally friendly and ishazardous to operate, no other process has been as efficient and itcontinues to be the major method of alkylation for octane enhancementthroughout the world. In view of the fact that the cold acid processwill continue to be the process of choice, various proposals have beenmade to improve and enhance the reaction and, to some extent, moderatethe undesirable effects.

U.S. Pat. No. 5,220,095 disclosed the use of particulate polar contactmaterial and fluorinated sulfuric acid for the alkylation. U.S. Pat.Nos. 5,420,093 and 5,444,175 sought to combine the particulate contactmaterial and the catalyst by impregnating a mineral or organic supportparticulate with sulfuric acid.

Various static systems have been proposed for contacting liquid/liquidreactants, for example, U.S. Pat. Nos. 3,496,996; 3,839,487; 2,091,917;and 2,472,578. However, the most widely used method of mixing catalystand reactants is the use of various arrangements of blades, paddles,impellers and the like that vigorously agitate and blend the componentstogether, for example, see U.S. Pat. Nos. 3,759,318; 4,075,258; and5,785,933.

The present application presents a significant advance in the technologyrelating to alkylation and, in particular, to petroleum refiningparaffin alkylation by providing both an effective method for thealkylation, novel olefinic feed and an apparatus for obtaining a highdegree of contact between the liquid catalyst and the fluid reactantswithout mechanical agitation thereby eliminating shaft seals, reducingcosts and improving acid product separation.

SUMMARY OF THE INVENTION

There are two aspects to the present invention. The first aspect is aprocess for the alkylation of paraffin, preferably isoparaffin witholefin or olefin precursor comprising contacting a fluid systemcomprising acid catalyst, alkane and olefin in concurrent flow,preferably downflow into contact in a reaction zone with internalpacking, such as a disperser (as hereinafter described) under conditionsof temperature and pressure to react said isoparaffin and said olefin toproduce an alkylate product. Preferably, the fluid system comprises aliquid and is maintained at about its boiling point in the reactionzone.

The second aspect of the present invention focuses on the olefin in thealkylation which is characteristic of an olefin precursor. The olefinprecursor is an oligomer of one or more tertiary olefins such as thedimer, trimer, etc. of isobutene or a material which corresponds to saidoligomer. In a particular embodiment, the present alkylation employsoligomers of tertiary olefins as the olefin component of the alkylationwith isoalkanes.

It has been surprisingly discovered that olefin reactants thatcorrespond to oligomers of olefins (for example, the longer chainoligomers of olefins made by polymerizing shorter chain olefins) whenreacted in an acid alkylation with an isoalkane react on a molar basiswith the constituent olefins of the oligomer, rather through theoligomers, per se, to produce alkylate product of the constituentolefin(s) and the isoalkane and not the alkylate of the oligomer per seas expected. The reaction may be carried out in an apparatus comprisinga vertical reactor containing a disperser or other suitable packing inthe reaction zone which may comprise the entire column or a portionthereof.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE is a schematic representation of the first aspect of thepresent apparatus in which the present alkylation process may be carriedout.

DETAILED DESCRIPTION OF THE INVENTION

The reaction of oligomer of tertiary olefins with isoalkanes is on amolar basis with the constituent tertiary olefins of the oligomer ratherthan the oligomers. The alkylate product corresponds to the reaction ofthe tertiary olefin and isoalkanes.

For the purpose of illustration and not a limitation of the process, itis believed that instead of the expected reaction between the oligomerand the isoalkane, the oligomer is cracked into its olefin componentswhich react with the isoalkane on a molar basis:

-   1) diisobutene+2 isobutane→2 isooctane (2,2,4-trimethyl pentane)-   2) triisobutene+3 isobutane→3 isooctane (2,2,4-trimethyl pentane)

The conventional view had been that the product of 1) would be a C₁₂alkane and the product of 2) would be a C₁₆ alkane whereas the productof reactions 1) and 2) is the same and is indistinguishable from aconventional cold acid alkylation product of the reaction:

-   3) 2 butene-2+2 isobutane→2 isooctane-   4) 3 butene-2+3 isobutane→3 isooctane

The great advantage of the present invention is that although acidalkylations are extremely exothermic and require substantialrefrigeration to maintain the reaction temperature in optimum range toprevent side reactions, the present reaction of the oligomers with theisoalkane to produce the alkylate in the same yields required lessrefrigeration making the process less expensive for the same yield ofuseful product.

One particular method of producing oligomer is that carried out in acatalytic distillation, for example, units formerly used to produce MTBEcan readily be converted to producing oligomer merely by changing thefeed to the reactor since the same catalyst serves both reactions.

Preferably, the oligomer comprises C₈ to C₁₆ olefins corresponding tooligomer prepared from C₃ to C₅ olefin. In a preferred embodiment theoligomer has 6 to 16 carbon atoms and corresponds to oligomers which areprepared from C₄ to C₅ olefins.

The widest use of the paraffin alkylation is for the preparation of a C₈gasoline component. The feed to this process is usually normal buteneand tertiary butane contained in a “cold acid” reaction usually withsulfuric acid or HF. The normal butene (butene-2, for example) is acomponent of light naphtha along with normal butane, isobutane andtertiary butene. The separation of the normal butene from the isobutenecan be effected by fractionation with difficulty because of their closeboiling point. A preferred way to separate these olefin isomers or thoseof the C₅ analogs is to react the more reactive tertiary olefin to forma heavier product which is easily separated from the normal olefins byfractionation.

Heretofore, the tertiary olefin was reacted with a lower alcohol, suchas methanol or ethanol, to form ethers, such as methyl tertiary butylether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary amyl methylether (TAME) which have been used as gasoline octane improvers but arebeing phased out because of health concerns.

The oligomerization of the tertiary olefin is also a preferred reactionwhen carried out on a naphtha stream with the separation of normalolefin being easily achieved by fractionation from the heavier (higherboiling) oligomers (mainly dimer and trimer). The oligomers may be usedas gasoline components but there are limits to the amount of olefinmaterial desirable or allowed in gasoline and it is frequently necessaryto hydrogenate the oligomers for use in gasoline. The most desirablecomponent for gasoline blending is C₈, e.g., isoctane (2,2,4 trimethylpentane).

The oligomer may be cracked back to the original tertiary olefins andused in cold acid reaction. However, the present invention has foundthat it is not necessary to crack the oligomer which may constitute theolefin feed to cold acid reaction with the alkane or may be co-fed withmono olefins. As noted above the result is the same product as the monoolefin alone with the additional benefit of a less exothermic overallreaction requiring less refrigeration and, hence, a lower energy costfor the alkylation.

The oligomerization process produces a heat of reaction that does notrequire the magnitude of heat removal as in the cold acid process. Infact, when the oligomerization is carried out in a catalyticdistillation type reaction, the heat of reaction is removed as boilup,which in this type of reaction is the lower boiling mono olefins andalkanes which are being separated from the oligomer. Thus, even thoughthere is heat produced in the oligomerization it is of no cost to theproduction of the gasoline since it is used in the fractionation, andthe operating cost of the alkylation unit is reduced by the use ofoligomer to replace some or all of the conventional short chain olefin.

In a preferred embodiment of the present alkylation process, a lightnaphtha stream comprising normal and tertiary olefins is contacted withan acid resin catalyst under oligomerization conditions topreferentially react a portion of the tertiary olefins with themselvesto form oligomers, and feeding said oligomers to an alkylation zone withan isoalkane in the presence of an acid alkylation catalyst to producean alkylation product comprising the alkylate of said tertiary olefinand said isoalkane.

The oligomerization may be carried out in a partial liquid phase in thepresence of an acid cation resin catalyst either in straight pass typereaction or in a catalytic distillation reaction where there is both avapor and liquid phase and a concurrent reaction/fractionation.Preferably, the feed is a C₄-C₅, C₄ or C₅ light naphtha cut. Thetertiary olefins may include isobutene, and isoamylenes and are morereactive than the normal olefin isomers and are preferentiallyoligomerized. The primary oligomer products are dimers and trimers. Theisoalkanes preferably comprise isobutane, isopentane or mixturesthereof.

When a straight pass reactor is used, such as that disclosed in U.S.Pat. Nos. 4,313,016; 4,540,839; 5,003,124; and 6,335,473, the entireeffluent comprising the oligomer, normal olefins and isoalkanes may befed to an acid alkylation reaction. The normal alkanes are inert underthe conditions of the present alkylation. Under alkylation conditionsthe isoalkane reacts with the normal olefin to form alkylate product andwith the individual constituent olefins of the oligomers to form thealkylate product. The implication of the result of the present processis that the oligomers are dissociated or in some manner make theirconstituent olefins available for reaction with isoalkanes. Thus, thereaction will produce:

-   1) isobutene oligomer+isobutane→isooctane;-   2) isobutene oligomer+isopentane→branched C₉ alkanes;-   3) isoamylene oligomer+isobutane→branched C₉ alkanes;-   4) isoamylene oligomer+isopentane→branched C₁₀ alkanes;    -   whereas it would have been expected that reaction 1) would        produce at least or mostly C₁₂ alkanes, reaction 2) would        produce at least or mostly C₁₃ alkanes, reaction 3) would        produce at least or mostly C₁₄ alkanes, and reaction 4) would        produce at least or mostly C₁₅ alkanes.

When a catalytic distillation reaction such as that disclosed in U.S.Pat. No. 4,242,530 or 4,375,576 is employed for the oligomerization, theoligomer is separated from the lower boiling normal olefins and alkanesin the reaction product by concurrent fractionation. The streams, normalolefins and alkanes (overheads) and oligomers (bottoms), may be unitedor individually fed to the alkylation or may be used individually withat least the oligomer being fed to the alkylation.

The present invention offers an improved contacting apparatus andprocess for producing and separating an alkylate product using sulfuricacid as catalyst. This same or similar device may also be used withother acids or acid mixtures.

The present process preferably employs a downflow reactor packed withcontacting internals or packing material (which may be inert orcatalytic) through which passes a concurrent multi phase mixture ofsulfuric acid, hydrocarbon solvent and reactants at the boiling point ofthe system. The system comprises a hydrocarbon phase and anacid/hydrocarbon emulsion phase. A significant amount of sulfuric acidis held up on the packing. Reaction is believed to take place betweenthe descending hydrocarbon phase and the sulfuric acid dispersed on thepacking. Olefin continuously dissolves into the acid phase and alkylateproduct is continuously extracted into the hydrocarbon phase. Adjustingthe pressure and hydrocarbon composition controls the boiling pointtemperature. The reactor is preferentially operated vapor continuous butmay also be operated liquid continuous. The pressure is preferentiallyhigher at the top of the reactor than at the bottom.

Adjusting the flow rates and the degree of vaporization controls thepressure drop across the reactor. Multiple injection of olefin ispreferred. The type of packing also influences the pressure drop due tothe acid phase hold-up. The product mixture before fractionation is thepreferred circulating solvent. The acid emulsion separates rapidly fromthe hydrocarbon liquid and is normally recycled with only a few minutesresidence time in the bottom phase separator. Because the products arein essence rapidly extracted from the acid phase (emulsion), thereaction and/or emulsion promoters used in conventional sulfuric acidalkylation processes may be added without the usual concern for breakingthe emulsion. The process may be described as hydrocarbon continuous asopposed to acid continuous.

Preferably, the disperser comprises a conventional liquid-liquidcoalescer of a type which is operative for coalescing vaporized liquids.These are commonly known as “mist eliminators” or “demisters”, however,in the present invention the element functions to disperse the fluidmaterials in the reactor for better contact. A suitable dispersercomprises a mesh such as a co-knit wire and fiberglass mesh. Forexample, it has been found that a 90 needle tubular co-knit mesh of wireand multi-filament fiberglass such as manufactured by Amistco SeparationProducts, Inc. of Alvin, Texas, can be effectively utilized, however, itwill be understood that various other materials such as co-knit wire andmulti filament teflon (Dupont™), steel wool, polypropylene, PVDF,polyester or various other co-knit materials can also be effectivelyutilized in the apparatus. Various wire screen type packings may beemployed where the screens are woven rather than knitted. Otheracceptable dispersers include perforated sheets and expanded metals,open flow cross channel structures which are co-woven with fiberglass orother materials such as polymers co-knit with the wire mesh expanded orperforated sheets. Additionally the multi-filament component may becatalytic. The multi-filament catalytic material may be polymers, suchas sulfonated vinyl resin (e.g., Amberlyst) and catalytic metals such asNi, Pt, Co, Mo, Ag.

The disperser comprises at least 50 volume % open space up to about 97volume % open space. Dispersers are position within the reaction zone inthe reactor. Thus, for example, the multi filament component and thestructural element, e.g., knit wire, should comprise about 3 volume % toabout 50 volume % of the total disperser, the remainder being openspace.

Suitable dispersers include structured catalytic distillation packingswhich are intended to hold particulate catalysts, or structureddistillation packings composed of a catalytically active material, suchas that disclosed in U.S. Pat. No. 5,730,843 which is incorporatedherein in its entirety and which discloses structures that have a rigidframe made of two substantially vertical duplicate grids spaced apartand held rigid by a plurality of substantially horizontal rigid membersand a plurality of substantially horizontal wire mesh tubes mounted tothe grids to form a plurality of fluid pathways among the tubes, saidtubes being empty or containing catalytic or non catalytic materials;and structured packings which are catalytically inert which aretypically constructed of corrugated metal bent at various angles, wiremesh which is crimped, or grids which are horizontally stacked one ontop of the other, such as disclosed in U.S. Pat. No. 6,000,685 which isincorporated herein in its entirety and which discloses contactstructures comprising a plurality of sheets of wire mesh formed into veeshaped corrugations having flats between the vees, said plurality ofsheets being of substantially uniform size having the peaks oriented inthe same direction and substantially in alignment, said sheets beingseparated by a plurality of rigid members oriented normally to and saidresting upon said vees.

Other suitable dispersers include: (A) random or dumped distillationpackings which are: catalytically inert dumped packings contain highervoid fraction and maintain a relatively large surface area, such as,Berl Saddles (Ceramic), Raschig Rings (Ceramic), Raschig Rings (Steel),Pall rings (Metal), Pall rings (Plastic, e.g. polypropylene) and thelike and catalytically active random packings which contain at least onecatalytically active ingredient, such as Ag, Rh, Pd, Ni, Cr, Cu, Zn, Pt,Tu, Ru, Co, Ti, Au, Mo, V, and Fe as well as impregnated components sucha metal-chelate complexes, acids such as phosphoric acid, or bonded,inorganic, powdered materials with catalytic activity; and (B) monolithswhich are catalytically inert or active which are structures containingmultiple, independent, vertical channels and may be constructed ofvarious materials such as plastic, ceramic, or metals, in which thechannels are typically square; however, other geometries could beutilized, being used as such are coated with catalytic materials.

The hydrocarbon feedstock undergoing alkylation by the method of thepresent invention is provided to the reaction zone in a continuoushydrocarbon phase containing effective amounts of olefinic andisoparaffinic starting materials which are sufficient for forming analkylate product. The olefin:isoparaffin mole ratio in the total reactorfeed should range from about 1:1.5 to about 1:30, and preferably fromabout 1:5 to about 1:15. Lower olefin:isoparaffin ratios may also beused.

The olefin component should preferably contain 2 to 16 carbon atoms andthe isoparaffin component should preferably contain 4 to 12 carbonatoms. Representative examples of suitable isoparaffins includeisobutane, isopentane, 3-methylhexane, 2-methylhexane,2,3-dimethylbutane and 2,4-dimethylhexane. Representative examples ofsuitable olefins include butene-2, isobutylene, butene-1, propylene,pentenes, ethylene, hexene, octene, and heptene, merely to name a fewand as described above may be oligomers of these olefins.

In the fluid process the system uses hydrofluoric or sulfuric acidcatalysts under relatively low temperature conditions. For example, thesulfuric acid alkylation reaction is particularly sensitive totemperature with low temperatures being favored in order to minimize theside reaction of olefin polymerization. Petroleum refinery technologyfavors alkylation over polymerization because larger quantities ofhigher octane products can be produced per available light chainolefins. Acid strength in these liquid acid catalyzed alkylationprocesses is preferably maintained at 88 to 94% by weight using thecontinuous addition of fresh acid and the continuous withdrawal of spentacid. Other acids such as solid phosphoric acid may be used bysupporting the catalysts within or on the packing material.

Preferably, the process of the present invention should incorporaterelative amounts of acid and hydrocarbon fed to the top of the reactorin a volumetric ratio ranging from about 0.01:1 to about 2:1, and morepreferably in a ratio ranging from about 0.05:1 to about 0.5:1. In themost preferred embodiment of the present invention, the ratio of acid tohydrocarbon should range from about 0.1:1 to about 0.3:1.

Additionally, the dispersion of the acid into the reaction zone shouldoccur while maintaining the reactor vessel at a temperature ranging fromabout 0° F. to about 200° F., and more preferably from about 35° F. toabout 130° F. Similarly, the pressure of the reactor vessel should bemaintained at a level ranging from about 0.5 ATM to about 50 ATM, andmore preferably from about 0.5 ATM to about 20 ATM. Most preferably, thereactor temperature should be maintained within a range from about 40°F. to about 110° F. and the reactor pressure should be maintained withina range from about 0.5 ATM to about 5 ATM.

In general, the particular operating conditions used in the process ofthe present invention will depend to some degree upon the specificalkylation reaction being performed. Process conditions such astemperature, pressure and space velocity as well as the molar ratio ofthe reactants will affect the characteristics of the resulting alkylateproduct and may be adjusted in accordance with parameters known to thoseskilled in the art.

An advantage of operating at the boiling point of the present reactionsystem is that there is some evaporation which aids in dissipating theheat of reaction and making the temperature of the incoming materialscloser to that of the materials leaving the reactor as in an isothermalreaction.

Once the alkylation reaction has gone to completion, the reactionmixture is transferred to a suitable separation vessel where thehydrocarbon phase containing the alkylate product and any unreactedreactants is separated from the acid. Since the typical density for thehydrocarbon phase ranges from about 0.6 g/cc to about 0.8 g/cc and sincedensities for the acid generally fall within the ranges of about 0.9g/cc to about 2.0 g/cc, the two phases are readily separable byconventional gravity settlers. Suitable gravitational separators includedecanters. Hydrocyclones, which separate by density difference, are alsosuitable.

One alkylation embodiment is shown in the FIGURE which is a simplifiedschematic representation of the apparatus and flow of the process. Suchitems as valves, reboilers, pumps, etc., have been omitted.

The reactor 10 is shown containing a disperser mesh 40. The presentdispersers achieve radial dispersion of the fluid or fluidized materialsin the reactor. The feed to the reactor comprises an olefin fed via line12 such as n-butene and an isoparaffin (e.g., isobutane) fed via line 14through line 52. Preferably a portion of the olefin is fed along thereactor via lines 16 a, 16 b, and 16 c. A liquid acid catalyst such asH₂SO₄ is fed via line 56 and make-up acid may be supplied through line38. The hydrocarbon reactants are fed to the reactor which is preferablya generally cylindrical column via line 58 and through appropriatedispersing means (not shown) into the disperser mesh 40, for example, aco-knit wire and fiberglass mesh.

The hydrocarbon reactants and non reactive hydrocarbons (e.g., normalbutane) are intimately contacted with the acid catalyst as thealkylation proceeds. The reaction is exothermic. The pressure as well asthe quantities of reactants are adjusted to keep the system componentsat the boiling point but partially in the liquid phase as the systemcomponents pass down flow through the reactor in mixed vapor\liquidphase and out through line 18 into decanter 30. In the decanter thesystem components are separated into an acid phase 46 containing thecatalyst, a hydrocarbon phase 42 containing the alkylate, unreactedolefin and unreacted isoparaffin, and non reactive hydrocarbons and avapor phase 44 which may contain some of each of the components and anylighter hydrocarbon components which are removed from the system vialine 50 for further handling as appropriate.

Most of the acid phase is recycled via line 24 and 56 into the reactor.Make-up acid may be added via line 38 and build-up spent acid removedvia line 48.

The hydrocarbon liquid phase is removed via line 22 with a portionrecycled to the top of the reactor via line 28. The remainder ofhydrocarbon phase is fed to distillation column 20 via line 26 where itis fractionated. Normal butane, if present in the feed, can be removedvia line 36 and the alkylate product is removed via line 34. Theoverheads 32 are primarily unreacted isoalkane which is recycled vialine 52 to the top of reactor 10.

Experimental Set up for Alkylation of Isoparaffin+Olefin

For the following examples the laboratory reactor is 15 feet high by 1.5inches diameter. It is packed with varying amounts and types of packingmaterial. The H₂SO₄ inventory is about 1 liter depending on the holdupof the packing used. The surge reservoir is about 3 liters and passesall the acid plus liquid hydrocarbon out the bottom to circulate atwo-phase mixture with a single pump. Feeds are introduced at the top ofthe reactor to flow down with the recycle mixture. Vapor is produced byheat of reaction plus ambient heat gains and helps force the liquidsdown through the packing creating great turbulence and mixing. Most ofthe vapors are condensed after the reactor outlet. Uncondensed vapor andliquid hydrocarbon product passes through an acid de-entrainer thenthrough the backpressure regulator to the de-isobutanizer. Mass flowmeters are used for feed flows and a Doppler meter measures thecirculation rate. Liquid products from the de-isobutanizer are weighed.However, the vent flow rate is estimated as being the difference betweenthe mass flow metered feed in and the weighed liquid products out. GCanalyzes all hydrocarbon products, including the vent. Titration is usedfor spent acid assay.

Operation

In the following examples the experimental unit circulates hydrocarbonand acid down flow at the boiling point of the hydrocarbons present.Pressure and temperature readings are logged electronically. The reactoroutlet temperature and pressure are used to calculate the amount of iC₄in the recycle hydrocarbon using an iC₄/Alkylate flash calculation.

A backpressure regulator that passes both product liquid and vapor tothe de-isobutanizer tower, maintains the pressure. A small amount of N₂may be used primarily to keep acid from backing up into the feed line.However, too much N₂ will cause a decrease in product quality bydiluting reactive isoparaffin in the vapor phase.

The circulation pump in the experimental setup circulates both the acidemulsion layer and the liquid hydrocarbon layer. Alternatively, thesetwo phases may be pumped separately.

The acid inventory is maintained by momentarily diverting the entirerecycle through a measuring tube using a three-way valve. The trappedmaterial settles in seconds to form two layers. The volume percent acidlayer and hydrocarbon layer is then used in conjunction with the Dopplermeter reading to estimate the volumetric circulation rates of bothphases.

The DP (pressure higher at the top or reactor inlet) is maintainedbetween 0 and 3 psi by manipulating the circulation rates and the heatbalance around the unit.

Different packing usually requires different vapor and liquid flow ratesto load to the same DP. Most of the time, the ambient heat gains and theheat of reaction provide adequate vapor (mostly iC₄) loading.

Because of refrigeration constraints, about 1-3 lbs/hr of extra liquidiC₄ may be introduced with the feed to provide some trim cooling. Thisexcess iC₄ is relatively small and does not significantly affect theiC₄/Olefin ratio since the circulating hydrocarbon rates are typicallyon the order of 100-200 pounds per hour. It is the circulatinghydrocarbon flow rate and composition that dominates the iC₄ ratios toeverything else. TYPICAL OPERATING CONDITIONS FOR C4 ALKYLATION IN THEEXAMPLES Feed olefin C4's Olefin in - lbs/hr 0.25-.50  Alky out - lbs/hr0.50-1.2  Rxn Temp out - F. 50-60 Rxn Psig out  6-16 DP - Psi 0.5-3.0Recycle rates: Acid phase - L/min 0.3-1   HC phase - L/min 1-3 Wt % iC4in HC recycle 75-45 Wt % H2SO4 in Spent acid 83-89 Wt % H2O in Spentacid 2-4 Fresh acid addition - lbs/gal alky 0.3-0.5 Packing Type 1 or2 - see notes below Packing Hgt in feet 10-15 Pack density lbs/ft3  5-14Notes:1. Packing type 1 is .011 inch diameter 304 ss wire coknitted with 400denier multifilament fiberglass thread every other stitch.2. Packing type 2 is .011 inch diameter alloy 20 wire coknitted with 800denier multifilament poly propylene yarn every other stitch.

EXAMPLE 1

Refinery C4 Olefins used as Feedstocks To the Lab Unit: 38% iB in Low iBtotal olefins methane 0.02 0.00 ethane 0.00 0.00 ethene 0.00 0.00propane 0.77 0.41 propene 0.14 0.16 propyne 0.02 0.00 propadiene 0.010.02 iso-butane 23.91 47.50 iso-butene 0.90 15.90 1-butene 20.02 10.491,3-butadiene 0.02 0.19 n-butane 22.63 10.79 t-2-butene 18.05 7.932,2-dm propane 0.09 0.00 1-butyne 0.00 0.01 m-cyclopropane 0.03 0.03c-2-butene 12.09 5.43 1,2-butadiene 0.00 0.01 3M-1-butene 0.26 0.04iso-pentane 0.98 0.02 1-pentene 0.06 0.82 2M-1-butene 0.01 0.01n-pentane 0.01 0.03 t-2-pentene 0.00 0.08 c-2-pentene 0.00 0.00t-3-pentadiene 0.00 0.08 c-1,3-pentadiene 0.00 0.00 unknowns 0.01 0.08100.00 100.00

Comparison of Refinery Produced Alkylate with Lab Unit Results usingSimilar low iB C4 Feed Plant A Plant B Lab 1 Lab 2 iC5 6.27 2.70 2.512.78 2,3-dmb 4.05 2.84 2.80 3.02 C6 1.63 1.19 1.00 1.15 2,2,3-tmb 0.200.17 0.18 0.19 C7 7.17 5.55 4.35 4.35 TM C8 53.88 61.76 66.84 66.93 DMC8 12.27 12.47 12.69 12.44 TM C9 5.04 4.22 2.89 2.74 DM C9 0.57 1.010.29 0.18 TM C10 1.14 0.91 0.70 0.64 UNK C10 0.51 0.54 0.29 0.29 TM C110.99 0.77 0.69 0.71 UNK C11 1.09 0.02 0.00 0.00 C12 4.37 1.71 4.72 4.60C13 0.00 1.58 0.00 0.00 C14 0.03 1.57 0.05 0.00 C15 0.00 0.13 0.00 0.00HV'S 0.05 0.04 0.00 0.00 UNK 0.74 0.83 0.00 0.00 sum 100.00 100.00100.00 100.00 Av MW 113.4 116.0 114.9 114.6 Bromine no. <1 <1 <1 <1Total Sulfur ppm <10 <10 <10 <10 TOTAL % TM 61.05 67.66 71.12 71.01 TMC8/DM C8 (ratio) 4.39 4.95 5.27 5.38 TM C9/DM C9 (ratio) 8.85 4.19 10.0815.57

Typical Vent Analysis: wt % hydrogen 0.000 oxygen 0.124 nitrogen 3.877methane 0.019 carbon monoxide 0.000 carbon dioxide 0.000 ethane 0.000ethene 0.000 ethyne 0.000 propane 1.066 propene 0.000 propadiene 0.000iso-butane 81.233 iso-butene 0.021 1-butene 0.000 1,3-butadiene 0.031n-butane 3.398 t-2-butene 0.000 m-cyclopropane 0.000 c-2-butene 0.000iso-pentane 0.968 1-pentene 0.000 n-pentane 0.000 C5+ 0.391

EXAMPLE 2

Effect of Isobutylene (iB) on Alky Quality lab 1 100% iB 38% iB low iBiC5 3.66 3.97 2.78 2,3-dmb 3.60 3.56 3.02 C6 1.42 0.52 1.15 2,2,3-tmb0.40 0.23 0.19 C7 5.27 5.08 4.35 TM C8 50.79 56.95 66.93 DM C8 11.7712.64 12.44 TM C9 6.07 4.22 2.74 DM C9 0.58 0.45 0.18 TM C10 2.06 1.330.64 UNK C10 1.14 0.67 0.29 TM C11 2.54 1.28 0.71 UNK C11 1.00 0.00 0.00C12 8.30 8.99 4.60 C13 0.07 0.00 0.00 C14 0.28 0.14 0.00 C15 0.12 0.000.00 HV'S 0.38 0.00 0.00 UNK 0.54 0.00 0.00 sum 100.00 100.00 100.00 AvMW 119.1 117.3 114.9 Bromine no. ˜1 <1 <1 Total Sulfur ppm <10 <10 <10TOTAL % TM 61.46 63.77 71.12 TM C8/DM C8 4.31 4.51 5.27 TM C9/DM C910.51 9.34 10.08

EXAMPLE 3

Propylene + iC4 Alkylation Sample Point product propane 0.01 iso-butane9.25 n-butane 0.32 iso-pentane 0.97 n-pentane 0.00 2,3-dm butane 2.072M-pentane 0.30 3M-pentane 0.14 n-hexane 0.00 2,4-dm pentane 15.592,2,3-tm butane 0.04 3,3-dm pentane 0.01 cyclohexane 0.00 2M-hexane 0.342,3-dm pentane 48.97 1,1-dm cyclopentane 0.00 3M-hexane 0.35 2,2,4-tmpentane 3.42 n-heptane 0.00 2,5-dm hexane 0.37 2,4-dm hexane 0.562,3,4-tm pentane 1.52 2,3,3-tm pentane 1.21 2,3-dm hexane 0.64 2,2,5-tmhexane 0.68 2,3,4-tm hexane 0.13 2,2-dm heptane 0.01 2,4-dm heptane 0.032,6-dm heptane 0.03 2,2,4-tm-heptane 1.83 3,3,5-tm-heptane 1.702,3,6-tm-heptane 1.16 2,3,5-tm-heptane 0.16 tm-heptane 1.002,2,6-trimethyloctane 2.32 C8s 0.20 C9s 0.20 C10s 0.98 C11s 1.62 C12s1.73 C13s 0.09 C14s 0.05 C15s 0.01 unknowns 0.01 heavies 0.00 100.00

EXAMPLE 4

Isobutane+Pentene 1 Alkylation Product Wt % C5 5.03 2,3-dmb 0.74 C6 0.35DM C7 1.14 C7 0.17 TM C8 22.26 DM C8 3.70 TM C9 52.40 DM C9 6.72 TM C101.51 UNK C10 0.56 TM C11 0.16 UNK C11 0.38 C12 3.68 C13 0.33 C14 0.11C15 0.08 HV'S 0.03 UNK 0.63 100.00 Avg MW 123.2 expected MW 128 feedolefin #/hr 0.25 Alky product #/hr 0.47

EXAMPLE 5

Oligomerization Product from C4 Feedstock with 38% iB in Total Olefins.(This Product was in Turn used as the Olefin Feed to the Lab AlkylationUnit) iso-butane 48.8 iso-butene + 1-butene 1.6 n-butane 11.2 t-2-butene14.3 c-2-butene 6.5 iso-pentane 1.0 t-2-pentene 0.1 unknowns 1.52,4,4-tm-1-pentene 4.7 2,4,4-tm-2-pentene 1.3 other C8′s 3.4 groupedC12′s 4.4 grouped C16′s 1.2 100.0

Oligomerization Effect on Alky Products using C4 Feed with iB=38% ofOlefins before after iC5 3.97 2.39 2,3-dmb 3.56 2.87 C6 0.52 1.172,2,3-tmb 0.23 0.20 C7 5.08 4.95 TM C8 56.95 58.34 DM C8 12.64 12.80 TMC9 4.22 4.15 DM C9 0.45 0.35 TM C10 1.33 1.29 UNK C10 0.67 0.57 TM C111.28 1.41 UNK C11 0.00 0.00 C12 8.99 9.41 C13 0.00 0.00 C14 0.14 0.11C15 0.00 0.00 HV'S 0.00 0.00 UNK 0.00 0.00 sum 100.00 100.00 Av MW 117.3118.3 Bromine no. <1 <1 Total Sulfur ppm <10 <10 TOTAL % TM 63.77 65.19TM C8/DM C8 4.51 4.56 TM C9/DM C9 9.34 11.75 Operating conditions:Olefin in - lbs/hr .25 .25 Alky out - lbs/hr .53 .53 Rxn Temp out - F52.0 52.2 Rxn Psig out 12.2 11.8 DP - Psi ˜1 ˜1 Recycle rates: Acidphase - L/min 1.0 1.0 HC phase - L/min 2.6 2.6 % 69 67 iC4 in HC recyclePacking Type 2 2 Packing Hgt in feet 15 15 Pack density lbs/ft3 7 7

EXAMPLE 6

Alkylate Quality from Isobutene+Isobutane or Oligomers of iB+iC4. iB DIBTIB+ IC5 3.66 3.97 3.41 2,3-dmb 3.60 3.70 3.18 C6 1.42 1.36 1.532,2,3-tmb 0.40 0.38 0.27 C7 5.27 4.96 6.39 TM C8 50.79 47.93 38.35 DM C811.77 8.92 12.91 TM C9 6.07 6.60 10.31 DM C9 0.58 0.81 1.10 TM C10 2.063.09 3.29 UNK C10 1.14 1.18 1.35 TM C11 2.54 2.53 2.72 UNK C11 1.00 1.790.00 C12 8.30 10.51 14.97 C13 0.07 0.31 0.07 C14 0.28 1.47 0.14 C15 0.120.29 0.00 HV'S 0.38 0.19 0.00 UNK 0.54 0.01 0.00 Sum 100.00 100.00100.00 Av MW 119.1 122.1 122.9 Bromine no. ˜1 ˜1 ˜1 Total Sulfur ppm <10<10 <10 TOTAL % TM 61.46 60.15 54.67 TM C8/DM C8 4.31 5.37 2.97 TM C9/DMC9 10.51 8.15 9.37

Operating Conditions: Feed olefin iB DIB TIB+ Olefin in - lbs/hr 0.250.40 0.25 Alky out - lbs/hr 0.49 0.78 0.48 Rxn Temp out - F 52 51.6 51.7Rxn psig out 13 13.5 5.7 DP - psi 2.5 1.1 ˜1 Recycle rates: Acid phase -L/min 0.8 0.5 1.0 HC phase - L/min 1.8 1.4 3.0 % 73 76 45 iC4 in HCrecycle Packing Type 1 1 2 Packing Hgt in feet 10 10 15 Pack densitylbs/ft3 6 6 7

EXAMPLE 7

Expected vs. Actual Alkylation Product MW's and Moles iC4 Uptake withVarious Olefins (e.g. in Theory 1 mole of C6 Olefin should React with 1mole of iC4 to Form a C10 Alkylate; MW=142)

Results Indicate Depolymerization Generating More and Lower MW Olefinsthat Combine with Additional iC4. Moles iC4 uptake per Average moleOlefin fed product MW Olefin Expected Actual Expected Actual Hexene-11.0 1.2 142 129 Octene-1 1.0 1.4 170 135 Di-isobutylene 1.0 1.8 170 122Tri-isobutylene+ 1.0 2.6 226 123

EXAMPLE 8

Isobutane+Pentene 1 Alkylation Product Wt % IC5 5.03 2,3-dmb 0.74 C60.35 DM C7 1.14 C7 0.17 TM C8 22.26 DM C8 3.70 TM C9 52.40 DM C9 6.72 TMC10 1.51 UNK C10 0.56 TM C11 0.16 UNK C11 0.38 C12 3.68 C13 0.33 C140.11 C15 0.08 HV'S 0.03 UNK 0.63 100.00 Avg MW 123.2 expected MW 128feed olefin #/hr 0.25 Alky product #/hr 0.47

1. A paraffin alkylation process comprising contacting alkane and olefinin concurrent flow in the presence of an acid catalyst into contact witha disperser to thereby achieve radial dispersion of the fluid materialsfor better contact under conditions of temperature and pressure to reactsaid alkane and said olefin to produce alkylate product.
 2. The processaccording to claim 1 wherein said alkane comprises isoalkane.
 3. Theprocess according to claim 1 wherein the acid catalyst comprises fluid.4. The process according to claim 3 wherein said fluid comprises liquid.5. The process according to claim 4 wherein the conditions are such asto maintain said liquid at about its boiling point.
 6. The processaccording to claim 5 wherein said process is hydrocarbon continuous. 7.The process according to claim 5 wherein said isoalkane comprises 4 to 8carbon atoms and said olefin comprises 3 to 16 carbon atoms.
 8. Theprocess according to claim 7 wherein flow is downward.
 9. The processaccording to claim 8 wherein said temperature is from about 0° F. to200° F.
 10. The process according to claim 4 wherein said dispersercomprises mesh of co-knit wire and polymer. 11-48. (canceled)
 49. Aparaffin alkylation process comprising contacting alkane and olefin inthe presence of an acid catalyst into contact with a disperser tothereby achieve radial dispersion of the fluid materials for bettercontact under conditions of temperature and pressure to react saidalkane and said olefin to produce alkylate product.
 50. The processaccording to claim 49 wherein said alkane comprises isoalkane.
 51. Theprocess according to claim 49 wherein the acid catalyst comprises fluid.52. The process according to claim 50 wherein said fluid comprisesliquid.
 53. The process according to claim 52 wherein the conditions aresuch as to maintain said liquid at about its boiling point.
 54. Theprocess according to claim 53 wherein said process is hydrocarboncontinuous.
 55. The process according to claim 53 wherein said isoalkanecomprises 4 to 8 carbon atoms and said olefin comprises 3 to 16 carbonatoms.
 56. The process according to claim 55 wherein flow is downward.57. The process according to claim 56 wherein said temperature is fromabout 0° F. to 200° F.
 58. The process according to claim 52 whereinsaid disperser comprises mesh of co-knit wire and polymer.